Echinoderms Flashcards
How many germ layers to echnioderms have?
3
What is the body symmetry of echnioderms?
radial
Do echnioderms have segmentation?
no
What is the coelem of echnioderms?
true coelem
Describe the nervous system of echnioderms
cephaliziation absent. has nerve net and eyespots
Describe the skeletal system of echnioderms
bumpy endoskeleton covered with spiny skin (made from calcium carbonate)
Describe how echnioderms feed
they have a mouth on underside. can be carnivores, herbivores, or detrivores
Describe the excretion of echnioderms
tube feet
Describe the circulatory system of echnioderms
water-vascular system (no blood)
Describe respiration of echnioderms
filter oxygen from the water
Are echnioderms sexual or asexual?
sexual
Examples of echnioderms
starfish, brittle stars, sea urchins & sand dollars, sea cucumbers, basket stars, sea lillies & feather stars
Are starfish really fish?
no
How many rays to most starfish have?
5
What are the pincers of starfish called?
pedicellarians
Do starfish have spines?
yes
Do starfish have eyespots?
yes
What do starfish do when they lose parts?
they regenerate them
What is the circulatory system of starfish
water vascular system
How do starfish feed?
stomach pushes out of the mouth, over food. enzymes digest food and stomach absorbs it. stomach goes back into starfish
What is a madreporite?
disc shaped opening in the body where water enters & exits
What does the ring canal do?
connects madreporite to radial canals in rays
Where are radial canals?
in arms, connect to tube feet
What are tube feet
hollow tubes with suction cups on end, poke out of the skeleton, retract if you pick them up-sensitive to touch, used to move, hold prey & open shells
Brittle stars are similar to what animal?
starfish
What do brittle stars do when the are in danger?
they lose a ray and regenerates it later
how to brittle stars feed?
they are filter feeders
How are sea urchins and sand dollars shaped?
globes or disk shaped; no rays
Are sea urchins carnivores or herbivores?
herbivores
What do sand sollars look like?
flat, covered with spines when alive
What do sea cucumbers look like
slug-life bodies with leatery skin & tentacles around the head, tube feet to move
What do sea cucumbers do when in danger?
expel internal organs for predators to eat. the internal organs then regenerate
Sea cucumbers make up __% of deep-sea ecosytem
90%
Basket star is a relative of what?
starfish
What do basket star arms look like?
long and branching
How do sea liles and feather stars feed?
filter feeding
What do sea lilies and feather stars look like?
long, feathery arms
What is the oldest class of echinoderms?
sea lilies and feather stars
